An Epidemiological Survey on Serological Diagnosis of Legionnella Infection in Seoul, Korea

ABSTRACT

Serological investigation of antibodies to Legionella species in 1,802 sera collected in seoul was conducted with indirect fluorescent antibody assay (IFA). With an antibody titer of > or =1128 to be positive, 17 (0.9%) of these sera were positive and 6 (35.3%) of positive sera showed cross-reactions between Legionella species. The number of sera with antibody titers of > or =1128 to L. pneumophila serogroup 1, L. pneumophila serogroup 4, L. pneumophila serogroup 5, L. bozemanii, L. micdadei, L. anisa were 6 (35.3%), 3 (17.6%), 3 (17.6%), 2 (11.8%), 1 (5.9%), 2 (11.8%) respectively. Among 17 positive sera, 10 (58.8%) sera were from male and 7 (41.2%) from female. An average age of them was 68.9 (+/-15.3; 27~89). Except for one serum, 16 (94.1%) of positive sera were from those older than 50 years old. The result suggests that the aged over 50 years old should be more careful of Legionella infection.